> > My understanding was that for trees it is preferred that fungi were > predominant, for grasses bacteria is the preferred predominant. For > veggies and flowers, and the like, I thought it was about 50% fungi and > 50% bacteria. > > Did I misunderstand?
Hi Bonnie, Yes it is more complicated than that. Among grasses, as among the row crop vegetables, there is a spectrum of needs and tolerances. Elaine discusses this in some of her audio CDs on the soil foodweb. For example, Poa pratensis, which we refer to as Kentucky bluegrass, is a grass which needs strong bacterial dominance. Fescues like it with more fungus, still bacterial but less so. And so on. Brassicas, says Ingham, are at the strong bacterial dominance end of the spectrum. I suppose this means that brassica root exudates select strongly for bacterial mutualists. In a rich organic soil with the presence of a suitable array of such bacteria, I assume that brassicas can have the bacterial services they seek, even if there are also a lot of fungus species/presence. The old JI Rodale literature contains several references to people who had rich composted soils that they were able to grow a wide spectrum of different plants in. The explanation offered, as I recall, was that compost/humus/soil organic matter had great buffering capacity (the pH thing). I think it is more likely that the rich, diverse foodweb in such composted soil had a full panoply of choices for each kind of plant to draw on in organizing microbial teams for its roots and leaves. Those teams could then mediate between the plants and the soil and get each plant what it needed. One thing I like about Ingham's stuff is she uses 'who' for organisms instead of 'what', as in 'let's see who's in there.' That suggests a sort of intimacy that we also of course need to have with our plants, as in not only are you a flower/veggie, but which one are you, which cultivar, what do you need from my growing? The bacterial/fungal dominance issue can only be part of our answers to those questions. Frank
